How did the South survive for as long as it did?

What really interests me about this war is the fact that the south survived for so long despite all of their crippling disadvantages. The north had better industrial business, weapons, and communications, whereas the south's only advantages were within its military leadership, defensiveness, and desire to make their own nation. I think the one advantage that kept them in the game for as long as they were was their cause. The north was sort of forced to fight through drafts and the like, whereas each soldier in the Confederate army truly believed in their cause and were willing to die for it.